What is masl? Mystery solved!

The caption reads:
At the summit of Gunung Raung, Indonesia, 31100 masl at 6 am on the crater rim, the usual route, not the highest point on the rim, 3332 meters, which is beyond.
Photo courtesy of Trevor Sharot.

Problem
I got an email accompanying a photo from a climb up a volcano in Indonesia. The caption read, ... masl ... I puzzled over this. I looked up mas and Indonesian and discovered that mas in Indonesian means sir or brother (to a man the same age or older) or gold.

Eventually, I gave up and had to reveal my ignorance. I wrote back:
What is Mas1 - a mountain, a peak, an area?

Straight away an email came back. It wasn't a one but a lower case letter l.
masl means metres above sea level. Initial letters.

As they say, learn something every day.


Useful Websites
In case you want to go climbing in Indonesia, many miles above sea level, some links:
In case you were wondering:
www stands for World Wide Web (a website, as opposed to an email or fax or phone contact)
The dot coms are international and / or for the USA.
GB stands for Great Britain.
in stands for Indonesia.
Home is the home page or landing page which then directs you to other pages contact page (email, address, tel); or hotel or restaurants or things to do or events or transport or buy now.

More photos:
trevorsharotphotography.com
indonesia-tourism.com
indonesiatourismboard.com
balitourismboard.or.in
https://www.facebook.com/Visit-Indonesia-Tourism-Office-Singapore-436644356438445/
http://www.indonesia.travel/gb/en/home (Official tourist board in the UK)

Author, Angela Lansbury, travel writer and photographer, author and speaker. Please share links to your favourite posts.